On 4 May 00, at 5:20, Snail Instruments wrote:


> Well, yes and no. There may be several ways to measure carbon dioxide
> concentration, but the very common approach is to use a pH probe separated
> from the measured solution by a gas permeable membrane. The CO2 diffuses
> from the sample to the inner solution and changes its pH. This change is
> then measured with the pH probe. Unfortunately this type of CO2 sensor
> suffers serious interferences from NH3 and volatile amines, which are both
> likely to appear in the fish tank water.

Hi,
 Josef, you don't feel sometimes that engineers needs to make
things too complicated...I think that maybe it's unnecesary to
measure pH or conductivity or something else, the problem is only to
keep some parameters like temperature and water saltiness in a
loving range for fish...
        Lives in aquarium is not an industrial process to be severe
monitorized. The simplest solution is to cover the top of aquarium for
minimize evaporation. Of course a little spectrophotometer ( to test if
water must be changed) is vital for fish... (mm..)
Vasile
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Surducan Vasile, engineer
mail: vasile@l30.itim-cj.ro
URL: http://www.geocities.com/vsurducan
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